Unusual aches and discomfort may be warning signs of serious illness

“It’s just a flesh wound” is one of the classic lines from the film Monty Python and the Holy Grail, uttered by the fearsome Black Knight after he suffers a seemingly fatal injury. But the stalwart and stubborn swordsman ignores his awful wounds and continues to fight (or at least tries to).

Many of us similarly shrug off pain as we battle through our day, attributing aches we never felt before to stress, overexertion or just another sign that we're growing older. Often we're right, but sometimes our bodies are trying to tell us that something more troubling is going on. They send out red flags — and we have to figure out what they mean.

Consider these cases: A woman experiences pain in her right shoulder. A man struggles with lower-back discomfort. An athletic man suffers through an apparent injury to his right thigh.

Each assumes the problem is a routine musculoskeletal ache.

Unfortunately, each is wrong.

The woman tells her physician that her shoulder hurts most an hour after eating. The man with lower back pain tells his doctor he's been having bouts of diarrhea. The athlete complains that his aching thigh wakes him up from a sound sleep.

These are all signs of something more serious than routine wear and tear. The woman turns out to be suffering from gall bladder disease. The man is diagnosed with a gastrointestinal illness. And the athlete has a bone tumor.

Red Flags to Watch Out For

Not all aches indicate the presence of disease, of course. But we need to be aware of the potential correlation between pain and illness. Pain in the same joint on both sides of the body, for example, or discomfort that does not ease with a change in position, is unlikely to be related to an injury.

“Chronic, exertional left-arm pain could be a sign of heart disease," says Dr. Craig Radnay, an orthopedic surgeon in New York. "Severe, acute right-lower quadrant pain is associated with appendicitis; and upper right-quadrant pain can indicate gall bladder disease." Lower back pain can also be a sign of kidney infection or kidney stones, or a peptic ulcer.

Dr. Gary Ostrow, an osteopathic physician in New York, says muscle pain signals a significant medical problem in up to 30 percent of all his cases. Mysterious pains are often indications that nearby organs are in distress, he says, because "any internal organ, when inflamed, can refer pain to muscles that have an overlapping nerve supply." Among the red flags you should never ignore: jaw soreness.

“Pain in the jaw muscles after exercise," he says, "could be a symptom of angina," a condition in which an area of your heart muscle doesn't get enough oxygen-rich blood, triggering pain or discomfort, usually in the chest. Jaw discomfort could also indicate an inflammatory vascular condition such as temporal arteritis, which affects the blood vessels that supply the head area.

When Medication Causes Unusual Pain

Medications can also contribute to puzzling aches. "Soreness in the tendons may be due to specific antibiotics that can lead to tendon tears," Ostrow says. Fluoroquinolones, a class of antibiotics (including levofloxacin and ciprofloxcin) used to treat respiratory infections, have been reported to cause tendon issues up to six weeks after treatment ends.

Cholesterol-lowering statins, such as Zocor, Lipitor and Crestor, can cause mild muscle pain. If that pain is severe, however, it may be an indication of rhabdomyolysis, a rare and potentially fatal condition in which muscle tissue begins to break down. If you take statins but feel weak or suffer from cramps or soreness, a simple blood test can determine if rhabdomyolysis is occurring. An adjustment in dosage or a holiday from the medications may be necessary.

Most muscle strains will heal within a few days or several weeks, Radnay says. But it’s still important to have pain evaluated — quickly if pain is severe or you feel numbness, of course; but even if the pain is relatively mild, you should see a doctor if it lasts more than two or three weeks. Delayed diagnosis and treatment, Radnay warns, "could lead to prolonged disability," and if the pain turns out to stem from disease, the health consequences could be dire.

So listen to your body when it tries to tell you something. A quick trip to the physician can help ease your mind — and your pain.